Does distilled water go bad?

In this brief guide we answer the question. “Does distilled water go bad?” and other questions pertaining to the subject at hand like how long can distilled water last or how to tell if your distilled water has gone bad.

Does distilled water go bad?

Not particularly. Distilled water is unlike other fluids and will stay safe to consume for an indefinite amount of time unless there is an addition (whether intentional or unintentional) of some other solute/solvent. 

Whether you’re drinking distilled water on a daily basis, or only buying it every once in a while for your steam iron, at some point you probably started thinking: does distilled water go bad?

If you have any questions or doubts about storage, shelf life, and “going bad” of distilled water, then this article is for you.

How to Store Distilled Water

The basic storage guidelines for distilled water are very similar to “plain” water. Keep the unopened bottle or container in a cool place away from sunlight. Once you open it, remember to always keep the container sealed tightly when not in use.

Storing Distilled Water for Home Appliances

Keep the product away from solvents and chemicals such as gasoline, paint. thinners, household cleaners, and dry cleaning chemicals. This is just an extra precaution. 

If you want to store the distilled water for a long term, a high-density polyethylene container is the best choice. Of course, there’s no point in buying one if you’re only storing a few ounces at a time for ironing.

Storing Distilled Water for Drinking

If you’re distilling water at home for drinking purposes, a glass container for water seems to be the best idea, as many home water distillers come with a glass tank. But a plastic BPA-free A food-grade bottle will be just fine too.

If you’d like to store some water in case of an emergency, one big or a couple of smaller containers will do the job. Again, make sure that they are food grade (made for contact with food)

The theory is the distilled water will stay safe indefinitely, provided that it’s sealed tightly, but personally, I just change that water every few months nevertheless. Especially if it’s in a plastic container.

How Long Does Distilled Water Last

When stored properly, like plain water, distilled water lasts pretty much indefinitely. For home appliances usage, distilled water can easily last a few years when unopened, and another year or two after opening if you take good care of it. 

When water is distilled at home, its quality is best for probably a week or so. After that time, it might start to smell somewhat stale. Of course, it’s still safe to drink and all, but you might want to discard it and go with a fresh batch.

Unopened bottled distilled water can last or more than 5 years. Distilled water, when opened,

can last for 4-7 days for drinking purposes.

Please note that the durations mentioned above are based on the best quality product, and may change with environmental and storage conditions.

How to Tell If Distilled Water Has Gone Bad

Commercially distilled water does not go bad very easily, since it has undergone a rigorous purification process and does not contain any nutrients for microbial growth. 

The occurrence of microbial contamination in distilled water is lower compared to other plain water. To tell if distilled water is not good or consumption, look for the following signs: Bad smell, floating particles and cloudiness.It is the most likely result of water that’s gone bad. 

In warmer climates, don’t take a sip directly from the bottle as it is quite possible that a tiny fraction of natural mouth bacteria get inside the bottle and start multiplying. So make sure to use a glass or something to pour in. Warmer temperature facilitates the multiplication of microorganisms. 

Unopened distilled water sealed inside the container does not get exposed to air, so it can stay fresh for quite a while. Distilled water is really pure, so even slight intrusions like air and various microparticles can enter it and alter the smell slightly. 

Unless you have a clear suspicion that the water is contaminated and it smells wrong, you need not to worry about it going bad. 

When opened, it might start to smell after a few days and doesn’t taste really well. Discard the water, if there is any noticeable change in colour or any impurity. In an opened bottle for a long time, green algae might start to grow. It is certainly time to throw the bottle away.

In short, if distilled water was stored properly, it should be perfectly fine, both for drinking purposes and use in home appliances. 

But as I already mentioned, after a few days of opening the bottle or distilling the water, it might start to “smell” slightly, and might not taste well because of that. That’s often more of an issue with the container than with the water itself.

However, if you notice that the smell of the distilled water has changed significantly, or find that any impurities got into the container, discard the water. The same principle applies if the taste is off. If it’s water for appliance use and looks and smells like usual, feel free to use it.


In this brief guide we answered the question. “Does distilled water go bad?” and other questions pertaining to the subject at hand like how long can distilled water last or how to tell if your distilled water has gone bad.